LOS ANGELES — Forty years ago, on the Friday before Thanksgiving, something very strange happened. A special television event that had been billed as “a dazzling lineup of stars, animation, adventure, music and visual effects” turned out to be two hours (including commercials) of “The Star Wars Holiday Special.”

In a way it made sense. It was the golden age of the variety show, and the cast of “Star Wars,” which had blown up the cinematic universe the year before, had made appearances on the “Bob Hope Christmas Special,” “The Richard Pryor Show” and “Donny & Marie.” It wasn’t entirely without precedent that the most popular movie of the previous year would have a variety show of its own.

Even so, it wasn’t quite what fans, or television viewers, were expecting.

The show opened with Wookiees. Ten minutes of Wookiees. Yes, Chewbacca had a family, and they lived in a rad treehouse loft with thick green shag carpeting on a planet called Kashyyyk. Wookiees speak Wookiee, not English, and there were no captions, so it was 10 full minutes of grunting and miming, which is a lot.

There was something of a plot — Han, played by Harrison Ford, and Chewie had to get home in time to celebrate “Wookiee Life Day.” But then Harvey Korman appeared in drag as an alien Julia Child. Bea Arthur sang, tended bar at the Mos Eisley Cantina and danced with Greedo. Diahann Carroll showed up for a virtual reality number, and Jefferson Starship played a hologram concert in a box. Luke (Mark Hamill) and Leia (Carrie Fisher) made appearances but so did Art Carney. Boba Fett was introduced in an animated sequence, and at the end, the Wookiees donned red robes, grabbed orbs, and marched into the sun. Princess Leia sang.

Not surprisingly, the special was never aired again; neither was it ever officially released by Lucasfilm. It took on an urban-legendary status, occasionally popping up in bootleg VHS trading groups; Carrie Fisher once joked that she had a copy to play at parties “when I wanted everyone to leave.”

Over the years, as “Star Wars” morphed from film to franchise, much has been written about its regrettable holiday special. And now, to mark its 40th anniversary, there’s even a play about its making. “Everybody went into it with good intentions,” said Andrew Osborne, author of “Special,” a semi-factual retelling of how it all went down that opens at L.A.’s Theatre of Note on Dec. 14.

Most of the writers and crew “were coming from a disposable pop culture perspective,” he said, and while George Lucas was hard at work creating a richly textured and expansive science fiction universe, “everyone [at CBS] was like ‘how do we work in more musical numbers?’”

It all started with the merchandise, or lack of it. When “Star Wars” premiered, no toys had even been developed. Christmas 1977 came and went without the fans getting to play Jedi and Stormtroopers at home, a situation Fox wanted to correct by Christmas 1978. But if the studio was going to sell toys, it needed something to remind kids how much they loved their heroes from a galaxy far, far away.

“Everybody agreed that a television special was a good idea,” said Jonathan Rinzler, who worked closely with George Lucas at Lucasfilm.

Lucas was very busy in 1978. Expectations were high for the sequel, and he was moving his production company to Northern California. So he didn’t have time to get very involved with the special. He came up with the general concept, Rinzler said: He wanted to expand on the Wookiees and introduce Chewbacca’s family; with concept artist Joe Johnston, he designed a “Clint Eastwood-style bounty hunter” named Boba Fett.

Then, according to first-person accounts, production was turned over to CBS, who put the project in the hands of veteran variety show writers and producers. The first director got frustrated with the budget and fast-paced production schedule of television, and quit. The costumes were so thick and bulky that the actors sometimes passed out. By the end, the whole thing had run out of money: The Wookiees in the final scene were shot wearing Chewbacca masks.

Osborne compares it to “the variety show version of ‘Murder on the Orient Express’: Everybody participated a little bit in the murder.”

He was 10 years old when “Star Wars” premiered, and he’d had the date of the holiday special circled on the family calendar for weeks. And then: “Almost immediately, from the opening credits, I started thinking, ‘Wait, why is Bea Arthur in this? Why is Jefferson Starship in this?’”

The Boba Fett cartoon — widely considered one of the few highlights — came in just shy of the hour mark in the special. After that, Osborne said, his family flipped to “The Love Boat.” (They weren’t the only ones: The special came second to “Love Boat” in the Nielsen ratings that night for the 8-9 p.m. hour, and second to Part 2 of the miniseries “Pearl” from 9-10.)

Richard Woloski, who with his wife, Sarah, co-hosts several “Star Wars” podcasts, was 9 years old when he watched it live; he remembers thinking: “This is all we’re gonna get until 1980, we better enjoy it.”

And he did — sort of.

“I enjoyed it. I was confused. In the ad for the holiday special, it said Han and Luke battle the Empire and get Chewie home before the Wookiee holiday. So I was like, when does this battle take place?”

The most important message of Life Day, he said, was clearly, “Buy toys.”

“I told my mom, ‘OK, when the commercials come on, grab a pen and paper and write down everything that you see,’” he recalled. “It worked on me like it was supposed to.”

Tricia Barr, co-author of “Ultimate Star Wars” and “Star Wars: The Visual Encyclopedia,” was about the same age when the special aired and while the Wookiees made a big impression on her, the familiar movie characters and the musical acts were “all mashing up in this really weird way.”

“Back in that time in the ’70s, television was a little weird and wacky anyways,” Barr said.

Eventually, the holiday special made it to YouTube, where it has found new life with many watching it, Osborne says, “like you look back on your portrait in a high school yearbook. At the time it’s mortifying but looking back it’s like, fine, everyone looks goofy in it. For a lot of people, that portrait was ‘The Star Wars Holiday Special.’”

He was inspired to write “Special,” he said, by trying to imagine who or what had happened to bring such a thing into existence.

“As a lifelong ‘Star Wars’ fan who had jarring memories of the holiday special, I always thought that it would be such an interesting story with so many interesting personalities involved,” he said. In his research, one thing that jumped out at him was how many people were actually involved in making it — and how all of them have actively distanced themselves from it since then.

Because a lot of those first-person anecdotes contradict each other, and some people have refused to talk about it at all, he describes the play as a “true-ish” version of events — “kind of a tall tale version of it,” with six actors playing dozens of parts.

As for people who have never seen the holiday special for themselves, “I wouldn’t tell my friends who aren’t into ‘Star Wars’ to watch it,” Barr said. But “if you really want to know ‘Star Wars’ history, then you should definitely check it out.”